Thermosensitive gels for the topical administration of diltiazem

In the present work thermosensitive systems were prepared, characterized and proposed for diltiazem administration in the topical treatment of anal fissures. Methylcellulose and Pluronic®F127 were used as gelling polymers. Some low toxicity-molecules as sodium glycocholate, citric acid and lactic acid were added to gel formulations as counterions to enhance diltiazem lipophilicity. The systems were characterized by sol-gel transition temperature, viscosity and rheological studies. The resulting data allowed to evidence which systems presented sol-gel transition. A change from Newtonian to plastic behavior at sol-gel transition temperature was observed. An increase in diltiazem pig skin permeability and two-fold skin accumulation was observed in the presence of citric acid.